| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | COVER ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
||||||||
|
||||||||||
NEWS & VIEWS |
Two studies from the Netherlands may suggest that consistent condom use can speed the regression of human papilloma virus (HPV)-related lesions on the cervix and on the penis and shorten the time it takes to clear HPV infections. The researchers believe that their findings add to the evidence that condoms can be a useful tool in the prevention of HPV-related cancers, though some experts consider the issue still unresolved.
Researchers from VU University Medical Center in Amsterdam and Albert Schweitzer Hospital in Dordrecht described their results in two articles in the International Journal of Cancer (2003;107:804–810 and 811–816). Both studies involved long-term (8 to 10 years) monogamous heterosexual couples in which the women had cervical intraepithelial neoplasia (CIN).
In the study that evaluated the effect of condom use on cervical lesions, women were randomized into two groups: one that used condoms during sexual intercourse for at least three months (64 women assessed) and one that did not use condoms (61 women assessed). The women’s lesions were followed by colposcopy, cytology, and a polymerase chain reaction assay for HPV at regular intervals. There were no statistical differences between the two groups of women in terms of age, smoking status, or general sexual history (number of partners, age at first intercourse, history of sexually transmitted diseases, and other factors).
After two years, the researchers found that the cumulative regression rate of cervical lesions was 53% in the group of women randomized to use condoms but only 35% in the women who were not using condoms (regression was defined as two consecutive findings of no colposcopically-noted CIN). Women with CIN2 or higher-grade lesions or HPV infection showed no difference in regression rates by condom use.
Condom use also appeared to have an effect on how quickly the women were cleared of HPV. Twenty-three percent of women in the condom group had clearance of HPV after two years, compared with 4% in the group not using condoms, where HPV clearance was defined as two negative tests for HPV regardless of type.
However, in women who still had CIN lesions or HPV infection after six months, there was no difference in the regression rate of either the HPV infection or the CIN lesion between the condom and noncondom groups.
Similar results were found in the study of men and HPV. In that study, men with HPV-related penile lesions (all of whose partners also had CIN) were evaluated after regular condom use for at least three months (57 men) or no condom use (43 men). Men who were assigned to the condom group had a mean time to regression of 7.4 months for flat penile lesions, compared with 13.9 months in the noncondom group. Regression of papular lesions was not significantly different in either group, and condyloma acuminata did not occur frequently enough for analysis. There was a trend toward greater likelihood of HPV clearance in the condom group (27% after two years) than in the control group (7%), although the difference did not reach statistical significance.
In this study, too, among men who still had lesions after six months, regression rates were not affected by condom use.
In both studies, the researchers speculate that the use of condoms inhibits the continued transmission of HPV between partners. That, in turn, would lower the viral load, allowing more rapid regression of lesions and more rapid elimination of the virus from the body. They recommend advocating condom use as a means of promoting HPV clearance and regression of HPV-related lesions.
Another expert, however, says several issues regarding condoms and HPV-related disease remain unresolved.
Diane Harper, MD, MPH, Associate Professor of Community and Family Medicine and of Obstetrics and Gynecology, Director of the Gynecologic Cancer Prevention Research Group at Dartmouth Medical School, and a member of the ACS’s Gynecologic Cancer Advisory Committee, noted that the Dutch researchers didn’t separate incident cases (occurring during the course of the study) of HPV infection from prevalent cases (present when subjects entered the study). The fact that regression rates differed little in the condom and noncondom groups after six months suggests condoms do not have an effect on prevalent HPV infections, prevalent CIN lesions, or prevalent penile lesions, she said.
The rates of regression in both of these studies of men and women, some followed for up to five years of condom use, are strikingly lower than natural history studies have reported, indicating that the study population was a combination of both incident and prevalent infections and lesions, Harper said. Most likely the attributable proportion of those with long standing infections and lesions regressing was quite small.
Most HPV infections and associated lesions are transient and regress spontaneously within a year. These would be the incident cases in this study, explained Harper. On the other hand, once infections and lesions persist for more than a year, such as the prevalent cases in this study, they are much less likely to regress.
Harper agrees that avoiding continued exposure to a high viral load might promote regression of incident cases. She also hypothesizes a second mechanism related to the "epithelial microtrauma" associated with condom use. These microscopic tears in the basal layer could increase exposure of immune system cells to viral antigens, thereby augmenting the immune response.
The question that still remains unanswered is whether condoms can substantially reduce exposure to HPV. Consistent condom use is clearly effective for the prevention of several other sexually transmitted diseases involving organisms that are transmitted in semen and primarily infect mucosal surfaces. By contrast, HPV is not transmitted in semen or bodily fluids, but is transmitted through skin-to-skin contact, and HPV infections often extend throughout the entire anogenital epithelium, far beyond the area covered by condoms. For this reason, the prevailing view has been that condoms cannot offer complete protection from the virus. Previous studies of whether condoms offer any degree of protection against HPV have been inconsistent, according to a 1999 report by the CDC.
Harper agrees with the CDC consensus and notes that the current study is more useful for guiding future research than as a basis of current clinical recommendations.
"Condoms may help with incident infections that are not well established, but most incident infections would not be detected without constantly sampling for HPV detection, which is not practical," Harper said. "In clinical practice, by the time most infections and lesions are found, they are much less likely to be influenced by condom use."
In addressing the problem of HPV, Harper emphasized public education, screening for and appropriate treatment of associated lesions, and research.
"We need to tell our patients that they cannot depend on condoms to prevent HPV transmission. When women and men become sexually active, there is a very high chance they will become infected with HPV. It is important for the women to tell their doctors when they become sexually active so that cervical cancer screening can begin at three years after sexual debut," she said.
"Our focus needs to be on community education - there is a vast lack of understanding and misunderstanding in all age groups of the community by both genders. Fortunately, both vaccines and topical drugs for prophylactic and therapeutic prevention of HPV are under development, and I’m optimistic that these new approaches will begin to change the way we think about controlling HPV and cervical cancer within the next 10 years," said Harper.
|
| ||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | COVER ARCHIVE | SEARCH | TABLE OF CONTENTS |
